Resettable switch mechanism

ABSTRACT

A small, low-power, remotely operated, manually reset, switch mechanism, which may be used for explosive munitions and like ordnance items consists of a motor, a rotary switch, a coupling unit and a rotary reset shaft located in coaxial relation, the motor and the switch being connected by the coupling unit which is the control element of the mechanism. The coupling unit includes a rotary sleeve connected with the switch shaft and concentric with the motor shaft. The shaft and sleeve may be spring biased to rotate in opposite directions. A detent ball, radially movable in a fixed retainer, which is concentric with and between the shaft sleeve, locks into a groove in the sleeve to hold the switch ON against the spring bias (thereby arming the device) and falls out into a groove in the motor shaft (thereby disarming the device) when the motor shaft is turned responsive to a remote control current applied to the motor.

U :1 fiQtlii tates afimlt 19 3,7,22 Zrando [4 1 July 10, 1973 RESETTABLE SWITCH MECHANISM [5 7] ABSTRACT [75] Inventor: Roy A. Zangrando, Clifton, NJ. A small, low-power, remotely operated, manually reset,

switch mechanism, which may be used for explosive munitions and like ordnance items consists of a motor, a rotary switch, a coupling unit and a rotary reset shaft located in coaxial relation, the motor and the switch [22] Filed: June 28, 1971 being connected by the coupling unit which is the control element of the mechanism. The cou lin unit in- [211 App! 157519 cludes a rotary sleeve connected with the swi tch shaft and concentric with the motor shaft. The shaft and [73] Assignee: The United States of America as represented by the Secretary of the Army, Washington, DC.

[52] US. Cl 102/70.2 R sleeve may be spring biased to rotate in opposite direc- [51] Int. Cl. F42b 5/08, F42b 9/08, F42b 21/38 tions. A detent ball, radially movable in a fixed re- [58] Field of Search l02/70.2 R, 70 R, tainer, which is concentric with and between the shaft 102/70 S, 76 R sleeve, locks into a groove in the sleeve to hold the switch ON against the spring bias (thereby arming the [56] References Cited device) and falls out into a groove in the motor shaft UNITED STATES PATENTS (thereby disarming the device) when the motor shaft is 3 511 183 5/1970 Geffner 102/702 turned responsive to a Control current applied 2,996,990 8/1961 Leaman 102/70.2 the motor- 3,078,80l 2/ 1963 Rzewinski 102/70.2 6 Claims 9 Drawing Figures Primary Examiner-Benjamin A. Borchelt Assistant Examiner-J. V. Doramus Attorney-Harry M. Saragovitz, Edward J. Kelly et al.

PATENIEU JUL 1 01m SBEH 1 0F 2 INVENTOR.

ROY AiANGR A o ATTORNEYS PMEMED JUL 1 0 I975 3. 744.422

sum 2 a? 2 INVENTOR. ROY A. ZANGRANDO RESETTABLE SWITCH MECHANISM The invention described herein may be manufactured, used and licensed by or for the Government for governmental purposes without the payment to me of any royalty thereon.

The present invention relates to an electromechanical rotary switch which is remotely activated by an electrical signal, but which is manually reset. Switches of this sort are particularly useful as safing and arming mechanisms for emplaced or fixed electrical or electronic explosive munitions and like ordnance items. More particularly, the present invention relates to a small, low-power, remotely operated switch mechanism for the control of emplaced ordnance items of the type referred to, wherein the. remote capability activates the switch control element in one direction but requires manual resetting.

It is therefore, an object of the present invention to provide an improved small, low-power, remotely operated switch mechanism which may be used for the electrical or electronic control of emplaced explosive munitions and like ordnance items wherein the safing feature precludes any danger to individuals approaching a disarmed munitions item since rearming must take place at the munition item itself.

It is further an object of this invention to provide a switch for general utility which is locked in positions until a combination of an electrical signal and manual rotation is applied simultaneously.

Previous systems for satisfying the requirement where the use of explosive munitions items are involved included explosive switches which required the re placement of either the switch or a module containing a number of such switches. For munitions items which necessitate frequent resetting, this system of operation is both awkward and time consuming. In addition, training is difficult and large quantities of switches may often be expended to insure the reliability of a certain lot of switches then in process of being used.

Other electromechanical devices for the safmg and arming of emplaced or fixed ordnance items have been developed but have been found often to involve defects, among which may be mentioned difficult mounting, limited switching capabilities, high power consumption in operation, low shock and vibration resistane, and switch decks and contact arrangements which are not variable after manufacture.

In accordance with the invention, the foregoing and other difficulties are overcome, and in addition, maximum use is made of commercial parts which may be available, thereby reducing the cost of low production quantities of such mechanisms. In accordance with the invention, four major components are required: a motor; a rotary switch which may have a plurality of stops and one or more switch elements; a coupling unit between the switch and the motor; and a rotary reset shaft which is adapted to be mounted on the shaft or control end of the switch when panel mounted. A rotary type motion is provided throughout because it is least susceptible to shock and vibration environments. For low power consumption and to insure reliability at low temperature operation the mouse-trap or cocked tension-spring principle is used, which produces a high energy release from a low energy activator.

The invention will furhter be understood from the following description when considered with reference to the accompanying drawing.

In the drawing,

FIG. 1 is a front view of a panel-mounted switch mechanism embodying the invention, with the mounting panel therefor partly broken away to show the switch mechanism.

FIG. 2 is a side view, in cross-section, of the switch mechanism shown in FIG. 1, taken on the section lines 2-2 of FIG. 1, and showing further details of the switch mechanism in accordance with the invention.

FIG. 3 is a side view of a motor as used in the mechanism in FIGS. I and 2, showing further details thereof in accordance with the invention.

FIG. 4 is a front view, in crosssection, showing further details in accordance with the invention, taken on the section lines 4-4 of FIG. 3.

FIGS. 5, 6 and 7 are schematic representations of certain elements of the mechanism shown in FIGS. 1 and 2 illustrating its operating sequence in accordance with the invention.

FIG. 8 is a schematic representation of another embodiment of the present invention.

FIG. 9 is a schematic representation of still another embodiment of the present invention.

Referring to the drawing, wherein like elements throughout the various figures are indicated by like reference characters and referring particularly to FIGS. 1 and 2, a safing and disarming switch It) for an emplaced explosive munition or ordnance item is provided with a central longitudinally extending flat operating switch shaft 12. The shaft I2 projects into a fixed threaded bearing element 13 which is adapted for mounting to the operating panel 14 of the ordnance item as indicated. The bearing element 13 is provided with a suitable lock nut 15 for holding it in a fixed position on the panel as indicated more clearly in FIG. 2. Tab 11, provided on disarming switch 10, projects into slot 38 on the panel 14 in order to hold the switch in a fixed position with respect to the panel 14.

The flat switch shaft 12 is provided with a round shaft extension or reset shaft 16 connected therewith and projecting forwardly of the bearing element 13 to receive a suitable operating knob as indicated in dotted outline at 17, although the shaft may be operated by a suitable tool if desired. The shaft 16 is slotted at its rear end to receive the flat forward end 18 of the switch shaft 12 as shown more clearly in FIG. 2.

The switch 10 is multisectioned and comprises as many sections as is desired, in stacked relation one behind the other, also as indicated in FIG. 2. The switch may be provided with suitable terminals as indicated at 19 to which are connected circuit leads as indicated at 20 for the safing and arming circuit of the munitions item with which the switch is used. Likewise the switch 10 may be arranged for an open or ciosed circuit condition in the position of rest or the normal position, as is desired for the control of the various arming circuits in munition items of this type.

In rear of the switch It), and coaxial therewith, is a coupling or control unit 22 and a rotary motor 23 all rigidly mounted together with the switch 10 in fixed relation thereto as indicated in FIG. 2. With this switch, the coupling unit and the motor preferebly both have cylindrical outer casings 24 and 25 respectively. Casing 24 includes a flat circular base 26 detachably mounted in tight abutting relation to a forward flat end 27 of the motor on two forwardly extending mounting studs 28 so that the motor casing 25 and the base 26 are in fixed relation to each other and with respect to the remaining rotary elements of the mechanism. These are the switch shaft 12 and the central shaft 29 for the motor which projects into the casing 24 of the coupling unit 22 as indicated in FIG. 2.

Referring now to FIGS. 3 and 4 along with FIGS. 1 and 2, the motor is further provided with a central circular cage 30, surrounding the shaft 29, which contains a flat spiral return spring 31. Spring 31 is connected at the inner end 32 with the motor shaft 29 and at the outer end 33 with the circular cage 30 which is fixed to the motor casing 25 and therefore non-movable. Adjustment of the return spring 31 is accomplished by positioning the outer end 33 at an appropriate point on the cage 30. The base is provided with a circular recess 34 to receive the spring 31 and cage 31) around the shaft 29 also as shown in FIG. 2 so that there is a clearance between the cage and the base 26 at all points. Electrical connections are provided with a motor through input leads indicated at 36 and as indicated in FIG. 2 these are connected through supply leads 37 to any remote control point. The control connections may be at a distant and remote position from the munitions item, for effecting safing thereof as will be described hereinafter.

The coupling unit 22, between the motor 23 and the switch 10, includes a plurality of operating and control elements in addition to fixed base 26 and the outer cylindrical casing 24. These elements are circular in configuration and in concentric relation to each other with respect to the switch shaft 12 and motor shaft 29, which are in axial alignment as indicated in FIG. 2.

The concentric elements to be considered are the rotary motor shaft 29 and a closely surrounding fixed sleeve 42 which projects forwardly from the base 26 and is carried thereby, preferably integrally therewith as shown in FIG. 2. The sleeve has a slight clearance with the shaft 29 and is provided with radial opening 43 in which a radially movable detent ball 44 loosely sits and rides in contacting relation with the shaft 29. The shaft 29 has an elongated groove 45 extending longitudinally thereof on one side to come into alignment with the ball when the shaft turns at the proper angle as will be described. Surrounding the fixed sleeve 42, which is a carrier for the ball, is a similar rotary sleeve 47 which also has an elongated longitudianlly extending slot 48 therein for aligning with the ball 44 and particularly rerounding the rotary sleeve 47, and out of contact therewith, is helical switch reset spring 53 in coaxial relation to the other elements. This is connected at the rear end 54 with the fixed base 26 and at the forward end 55 with the rotary hub element 49. In this way, like the motor shaft, the switch shaft 12 with the rotary hub ele ment 49 is biased to move toward a position of rest as a result of the spring tension. In the present example, as viewed from the forward end of the mechanism, the hub 49 and the switch shaft 12 are spring biased to rotate in the counter-clockwise direction to a position of ceiving the ball in one position of rotation, as shown in FIG. 2.

FIGS. 1-7 show only one opening 43 in the sleeve 42 in which the ball 44 rides, and one set of corresponding slots 45 and 48. It should be noted, however, that a plurality of these elements may be disposed about the shaft 29. For example, FIG. 9 shows three radial openings 43 disposed at l20 intervals around the shaft 29 with three corresponding detent balls 44 and sets of 'slots 45 and 48.

The rotary sleeve 47 is part of and is carried by a rotary hub element 49 which is connected with the rear end of the switch shaft 12 through a socket 541 projecting centrally and forwardly therefrom and having a rectangular opening 51 therein for receiving the rear end-of the switch shaft 12 all as shown more clearly in FIGS. 1 and 2. There is a slight running clearance between the fixed sleeve 42 and the rotary sleeve 47, so that the switch shaft 12 and the hub element 49 turn freely in response to rotation of the reset shaft 16. Surrest, whereas the motor shaft 29 is biased to rotate in the opposite direction to a position of rest.

The operation of the mechanism is such that the detent ball 44 always lies in the radial opening 43 which is fixed with the base 26 in the carrier sleeve 42, and freely moves radially into either one or the other of grooves 48 and 45, respectively, in the rotary sleeve 47 and the motor shaft 29. In either position it holds the one or the other of the elements with which it is engaged in a fixed position since it is fixed in the nonrotatable fixed carrier sleeve 42. It thus acts as a detent to hold either the motor shaft 29 against its return spring action or the hub element against its return spring action, as the case may be. This mode of operation and the functioning of the detent will better be understood from a consideration of the schematic diagramtic forms of the apparatus shown in FIGS. 5, 6 and 7.

Referring particularly to FiG. 5, the rotary sleeve 47, which is connected through the hub 49 with the switch shaft 12, is shown latched in the armed or ON position of the switch, so that the munition items with which it is connected are ready for firing when the concentric elements of the coupling unit are in the relative positions shown in FIG. 5. Here the hub or sleeve 47 and the switch shaft are restrained, by the detent ball 44, in the extreme clockwise position against torque of the return or activating spring 53. The detent ball 44 is free to move radially in the detent hole 43 in the fixed carrier sleeve 42 accordingly as influenced by the hub or sleeve 4'7 and the motor shaft 2%. In the position shown it is restrained in the groove 48 by the shaft 29 and thus locks the rotary sleeve 47 to the fixed sleeve 42 and holds the switch in the ON or armed position in the present example.

Upon application of an electrical signal through supply leads 37 to energize the motor 23, the motor shaft 22 rotates in counter-closkwise direction to the position shown in FIG. 6 wherein the groove 45 is directly in alignment with the detent ball 44. The latter is free to fall out of the notch 48 and into the notch 45. Actu ally the ball is forced into the groove 45 from the groove 48 by the hub or sleeve 47 as it is forced to rotate in the direction of the arrow (or counterclockwise) by reason of the force of the return or activating spring 53. The switch shaft 12, which is connected to rotate with the sleeve 47, then positions the switch 111 to the disarmed or OFF position. Stop rings may be provided, as indicated at 57 in H6. 2 to set the switch in any desired stop position as may be-required with respect to the contacts then in use. The stop pin 56 on the hub 49 contacts tabs appropriately placed on the stop rings 57. The stop rings thus control the contact position when moved by the return or activating spring 53. As indicated in FIG. 7, the motor shaft 29 is now held mechanically in the energized position by the detent ball 44 being forced into the groove 45. Although the disarming button 38 may be released to open the contacts 39, the shaft 29 thus cannot move or return to the armed position. The emplaced explosive munition item is thus made saft to be approached and handled, the disabling being effectuated from a remote point of control.

To reset, that is rearm, the mechamism, it is necessary to manually rotate the reset shaft 16 which extends through the panel when the device is installed as indicated in the drawings. This rotation repositions the switch contacts and the hub 49 and likewise the sleeve 47 connected therewith to the position shown in FIG. 6. The detent ball 44 is then permitted to be forced outwardly by the shaft 29 as it is rotated to the armed position in response to the biasing force of the reset spring 31, so that the ball enters the groove 48 and the parts are again in the position shown in FIG. 5. In that position the hub 49 and sleeve 47, and likewise the switch shaft 12, are locked in place by the motor shaft 29 and ball 44.

It may be noted that the angular throw of the motor and of the switch may be of any desired magnitude, such as for example 30, in which case a maximum of six poles per deck of the switch sections may be provided in the usual installation.

From the foregoing description, it will be seen that the rotatable elements of the remotely operated switch mechanism, that is, the motor shaft 29 and the hub 49 are both spring biased to a return or stop position. In the present example, the motor shaft 29 may be considered to be biased in the clockwise direction of rotation by the return spring 31, as shown in FIG. 4, to the stop position indicated in FIG. 5 wherein the groove 45 is turned so that the detent ball 44 is locked in the groove 48 to hold the sleeve 47 in the retracted position against the actuating force of the activation or reset spring 53. Likewise the hub 49 is biased to rotate in the counter-clockwise direction to the position shown in FIG. 7 for example, with the groove 48 moved beyond the detent ball 44 and to force the ball into the groove 45 of the shaft 29, thereby to lock the motor shaft 29 in the activated position against the restoring force of the spring 31.

The construction of the coupling unit thus is such that it provides an outer casing 24 of which the fixed base 26 is part and the latter is rigidly mounted against the motor casing 25 on the studs 28 so that the motor casing and the casing base elements of the coupling unit are fixed in position, along with the switch 10, through the mounting means, from the panel 14. The motor shaft 29 extends from the motor along the axis of the unit or mechanism and is surrounded by the fixed sleeve 42 of the base 26 which holds the detent ball 44 in the radial opening 43 therein while the ball 44 enters the groove 48 and thus holds the hub 49 (through sleeve 47) locked in the retracted position shown and indicated in FIGS. 2 and 5.

The coiled biasing or reset spring 53 for the hub 49 and switch shaft 12 is connected with the fixed base 26 at 54 and with the hub at 55 while motor shaft spring 31 is connected with the motor casing 25 and with the shaft 29 so that both are fastened to the same fixed element which is the sleeve 42 and the base 26 as indicated in FIG. 5 by the ground lines 58. Both rotatable elements carry complimentary notches or grooves 45 and 48, respectively, which are adapted to just receive the detent ball when the other element is passing the ball 44 out of engagement therewith. In other words, the groove 48 and the groove 45 are of substantially the same depth to complement the hole 43 in the fixed sleeve to just contain the detent ball without excessive play or motion while permitting both of the rotary elements to move freely in response to the biasing force of their respective activating or return springs.

With this construction, the shaft 29 turns to lock the ball into the sleeve 47 and hold it in the locked and retracted or armed position as shown in FIG. 5, while the sleeve 47 serves to press the detent ball into the shaft 29 and hold it in the locked and retracted or unarmed position as shown in FIG. 7. In FIG. 6, as noted herein before, the motor has been energized to rotate the detent ball 44 and to permit the activation spring 53 to return the sleeve 47 to its position of rest as shown in FIG. 7, thereby turning off the arming switch and the circuit connection therewith as hereinbefore described.

The basic invention as described above is also adaptable to other functional applications. For instance, elimination of the return spring 53 eliminates the remote actuation capability but leaves a manually controlled switch which can be actuated from one of the positions only when a concurrent electrical signal is applied. Reference is now made to FIG. 8 in which another groove 58 is added to the sleeve 47. This produces a switch which cannot be manually actuated in either direction without a concurrent electrical signal. For example, if a switch for security reasons must be locked in position and must be guarded against unauthorized switching, this embodiment of the present invention could be used. Thus, only with a combination of manual rotation and a remotely energized electrical signal, applied simultaneously, can the switch position be changed.

There is thus provided a small, low-power switch mechanism which may be used for the control of emplace explosive munitions and the like, of low cost construction adapted to utilize readily available commercial parts and to be resistant to shock and vibration and easily mounted for use. This mechanism further has the safety feature that it must be manually reset and may be remotely disarmed by switch operation.

I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

I claim:

1. A switch apparatus comprising:

a fixed housing containing a fixed first sleeve having a radial aperture therein;

a first shaft mounted to rotate within said first sleeve between first and second positions and having an external first longitudinal groove therein;

spring means biasing said first shaft towards said first position;

actuating means for rotating said first shaft against said spring means to said second position;

a second sleeve surrounding said first sleeve,

mounted to rotate between third and fourth positions, and having at least one internal second longitudinal groove therein;

a rotary switch attached to said housing and having a second shaft coaxially connected to said second sleeve for rotation therewith;

a detent ball positioned partly within said radial aperture; said ball being movable into said second groove when said second sleeve is in said third position and movable into said first groove when said first shaft is in said second position; said ball and said first shaft locking said second sleeve in said third position when said first'shaft is in said first position; and

external means connected to said second shaft for rotating the latter and said second sleeve from said fourth position to said third position.

2. A switch apparatus as in claim 1, wherein said actuating means is an electric motor having a preselectable angular throw.

3. A switch apparatus as in claim I, wherein said second sleeve has only one internal groove, whereby said ball and said second sleeve locks said first shaft in said second position when said second sleeve is in said fourth position.

4. A switch apparatus as in claim 3, further including second spring means biasing said second sleeve towards said fourth position.

5. A switch apparatus as in claim 1, wherein said second sleeve has two of said internal grooves, one for each of said third and fourth positions, whereby said an emplaced explosive munitions item or the like. 

1. A switch apparatus comprising: a fixed housing containing a fixed first sleeve having a radial aperture therein; a first shaft mounted to rotate within said first sleeve between first and second positions and having an external first longitudinal groove therein; spring means biasing said first shaft towards said first position; actuating means for rotating said first shaft against said spring means to said second position; a second sleeve surrounding said first sleeve, mounted to rotate between third and fourth positions, and having at least one internal second longitudinal groove therein; a rotary switch attached to said housing and having a second shaft coaxially connected to said second sleeve for rotation therewith; a detent ball positioned partly within said radial aperture; said ball being movable into said second groove when said second sleeve is in said third position and movable into said first groove when said first shaft is in said second position; said ball and said first shaft locking said second sleeve in said third position when said first shaft is in said first position; and external means connected to said second shaft for rotating the latter and said second sleeve from said fourth position to said third position.
 2. A switch apparatus as in claim 1, wherein said actuating means is an electric motor having a pre-selectable angular throw.
 3. A switch apparatus as in claim 1, wherein said second sleeve has only one internal groove, whereby said ball and said second sleeve locks said first shaft in said second position when said second sleeve is in said fourth position.
 4. A switch apparatus as in claim 3, further including second spring means biasing said second sleeve towards said fourth position.
 5. A switch apparatus as in claim 1, wherein said second sleeve has two of said internal grooves, one for each of said third and fourth positions, whereby said second sleeve is locked in either of said third and fourth positions when said first shaft is in said first position and cannot change position without simultaneous acuation of said actuating means and rotation of said second shaft.
 6. A switching apparatus as in claim 1, which forms part of a safing and arming apparatus for the control of an emplaced explosive munitions item or the like. 